Means for trimming shaped grinding wheels



June 9, 1942. A, c. wlcKMAN 2,286,046

MEANS FOR TRIMMING SHAPED GRINDING WHEELS Filed OC, l5, 1940 4 SheetS-Shee l um, an WHmLk June 9, 1942.

. A. c.v wlcKMAN FOR TRIMMING SHAPED GRINDING WHEELS MEANS Filed Oct. l5. 1940 4 Sheets-Sheet 2 June 9, 1942. A. c. wlcKMAN MEANS FOR TRIMMING SHAPED GRINDING WHEELS Filed Oct. l5, 1940 4 Sheets-Sheet 5 a ff June 9, 1942. A Q wlcKMAN `2,286,046

MEANS FOR TRIMMING SHAPED GRINDING WHEELS Filedoot. 15, 1940 4 sheets-sheet 4 Patented June 9, 1942 WHE `Axel Charles Wickman, Tile Hill, Coventry,

England y, Application October 15, 1940,'SerialNo. 361,325

` In Great Britain'Oetober 9, 1939 This invention has for its object to Vprovide improved means for trimming a grinding wheel having a helically shaped peripheral abrasive surface adapted for use in the grinding to a deslred form the teeth of gear wheels, spline shafts "and other like bodies.

The invention also comprises the combination of a rotary trimming roller adapted to effect the required trimming by a'crushing action on the grinding wheel, a slide on which the rotary trim- 'ming roller is mounted, and which is movable towards and away from the peripheryv of the grinding wheel. another slide which carries the first slide and is movable in a direction along the periphery of the grinding wheel, means for ac' tuating the first slide, a reversible mechanism fOractuating the second slide, means for rotating the grinding wheel and the reversible mechanismfa clutch for controlling the action' of the reversible mechanism, and means associated with the second slide for controlling the movements Aof both slides and thereby causing the trimming roller to pass through successive operation-cycles automatically.

In the yaccompanyir'ig sheets of drawingsi Figure 1v is a front elevation, Figure 2- a side explanatory "elevation, and Figure 3a plan, of means constructed" in accordance with` the inventiony for trimming the helically shaped-r periphery of a -grinding `wheel used for grinding the teeth of gear wheels. n

, Figure 4 is a section ure 1 r l Figure 5 Ais a fragmentary plan view illustrating'to a larger'scale than the other figures, a part of the mechanism employed for moving the trimming roller. y A

In carrying the invention into effect as shown,

on the line 4 4 of Fig- I employahard steel trimming roller a having vits periphery shaped to a V-form corresponding with the cross section of the helix-groove of the grinding wheel b tobe trimmed. Or the trimmingrolle'r may have formed around its pe- 'riphery `two or more similarly shaped circumferential grooves so that it can engage the grinding wheelgroove at several adjacent positions. This roller a is freely rotatable and can not only be pressed against the peripheral surface ofthe grinding wheel but can also travel along that surface so as to cause the whole length of the helical groove `of they 'grinding' wheel to ibe subjected to the action of the roller, rotation of the Aroller'being obtained from its engagement with the rotating grinding wheel. The required'trimming of the grinding wheel b obtained by the crushing action of the trimming rollerga lon the wheel, causing the helical groove in the latter to n source receive the form imparted to it by the roller.

For enabling the trimming operation to be effected automatically, I employ a slide c on which the roller a is so mounted that it can rotate Vfreely. This slide c is movable at right angles to the axis vof the grinding wheel b, and is mounted on another slide d which is movable parallel Awith that axis. Movement of the first slide c in each directionis effected by fluid operated means which may conveniently consist of a plunger e carried on the second slide d and co-operating with a cylinder f mounted on or formed in the first slide, a pair of pipes g, h, being provided for conducting fluid to and from oppositeends of the cylinder. The plunger e is formedwith an enlarged headel which isA situated in the'l cylinder f so that when pressure fluid is supplied by the pipes g, h, to both `ends of the cylinder, the rst slide c will move the trimming roller a towards the grinding wheel b, but when pressure fluid is supplied to one end only 4of the cylinder by the pipe h, the rfirst slide will retract the trimming roller from the grinding wheel. Movement of the second slide d in each direction is effected by a screw i engaging a nut j on this slide and rotatably mounted ona part k which carries the second slide.

Rotation of the screw is effected from any convenient source of motion which also servesr to rotate the grinding wheel b. This source of motion may be an electric motor as m from which a shaft n carrying the grinding `wheel b is ordinarily driven in the work-grinding operation through belt gearing indicated as a whole by l, the rotation of the screw i being vthen effected through reduction gearing at an appropriate slow rate. But preferably and as shown the said consists of a separate small electric motor o whichtis brought into action only in the wheel trimming operation, this motor serving to rotate 'both the grinding wheel b and the screw i of the second slide d through a rotary shaft p to which the motor is connected by a wormq and worm wheel r, the motor m being then used for driving the wheel b at an appropriate higher speed the shaft s has secured to it a gear wheel y which" is connected by a pair ofv interengaginggear wheels z to another gea-r wheel 2v on the' adja- 1 cent end of the second shaft t, the latter shaft and the shafts p, s, being arranged parallel with each other at right angles to the axis of the' grinding wheel b. Splined on the second shaftt is a slidable helical gear Wheel 3 which engages another helical gear wheel 4 on the ladjacent end of the third shaft u, the latter shaft being situ-v ated parallel With the axis of the grinding wheel b` and having its other end connected by inter- Vengaging gear wheels 5 with an extension 6 on the adjacent end of the screw iabove mentioned. 'Ihe fourth shaft v has secured to it a small Bear wheel 'l which engages the gear wheel :c on the motor-driven shaft p. Also secured on the fourth shaft u is another gear wheel 8 which is of considerably larger diameter thanthe gear wheel 1 and which engages a further gear wheel 9 freely mounted on the rst shaft s, the latter gear wheel being of smaller diameterthan and situated at a suitable distance from the other freely rotatable gear wheel w on the rst shaft. For alternatively connecting the two gear wheels w, 9, to the shaft s, and thereby controlling the'forward and reverse movements of the second slide d there is employed a fluid-operated clutch comprising a pair of outer parts I respectively formed on or secured to the gear wheels w, 9, and an intermediate part II slidably keyed to the shaft s, Athentermediate part being formed at each end with a single tooth or projection I2 for engaging a single complementary notch or recess I3 in the adjacent outer part of the clutch, so that the component parts of the clutch can be interengaged only when Ain predetermined relative positions. Alternatively a single toothor projection as above ,described may be formed only on that end of the intermediate clutch part which is adapted to engage the outer clutch part on the gear wheel w,

'the other end of the intermediate part being adapted in any convenient and ordinary manner to engage the other outer clutch part. f

When the intermediate clutch part I I is in on of its extreme positions it engages the outer clutch part I0 on the gear wheel w and the motor o can serve to rotate the screw (in the direction for imparting forward movement to the second slide d) through the parts q, r, p, w, s, y, z,

`2, t, 3, 4, u, l and 6. In its other extreme position the intermediate clutch part IIengages the outer clutch part I0 on the gear wheel 9 and the motor can serve to rotate the screw i (in the direction for imparting quick return movement to the slide d) through the parts q, r, p, m, 1, v, 8, 9, s, y, z, 2, t, 3,4, u, 5 and 6.

The fluid-operated means for actuating the slidable part II of the clutch consist of a pair of coaxial plungers I4, I5 which are slidable in a pair of corresponding cylinders I6, Ifl, a pair of pipes I 8, I9 being provided for conducting fluid to and from the cylinders. The plungers I4, I5,

are formed on or secured to opposite ends of a short toothed rack which engages a pivoted toothed sector 2l, the latter having secured to it a lever 22 through which movement can be imparted to the slidable clutch part II by the interaction of a projection 23 on the lever and a peripheral groove 24 in the said clutch part. The plunger I5 and its cylinder I1 are of greater diameter than the plunger I4 and its cylinder I6 so th'afwhen pressurelfluidfis.supplied by the pipes I8, I9, to both of thesecylinders, the slidable part lI of the clutch will engage the clutch part I0 on the gear wheel w for causing forward movementof the second slide d, but when pressure uid'is supplied to the cylinder I6 only by the pipe I8 the slidable clutch part will engage the clutch part I0 on the gear wheel 9 for causing quick return movement of the secondk slide.

Another clutch consisting of a pair of interenlgageayble parts 25, 26, is provided between the motor-driven shaft p and another coaxial shaft 21 which is connected to the grinding wheel shaft n through helical gearing 28, the clutch part 25 being slidably mounted on the end of the engagementby a single complementary notch or recess 251 in the other clutch part 25 so that the ed an appropriate valveand tappet mechanism f adapted to cause thev trimming roller a to move automaticallythrough the trimming cycle. This mechanism comprises a valve 30 of any convenient form, and a tappet 3I adapted to actuate the valve. The tappet 3| is vcarried by or forms part of a, slidable member 32 mounted in end bearings 33. The slidable member 32 is pro-v vided with a pair lof abutments 34, 35 through `.which the said member can be ,moved in opposite directions by another abutment 36 on the second vslide d for controlling the action ofthe valve 30, the latter being provided with a springloaded operating member 31 adapted to be actuated by an adjacent inclined surface of thetappet. To the body part of the valve 3l!v are connected the adjacent ends of a pressure-fluid supply pipe 38, a fluid exhaust pipe 39, and the pipe ,I9 leading to the cylinder I'I of the operating means for the gearfcontrolling clutch, the latter pipe having connected to it the pipe g of the fluid operated means for actuating the first slide c.` The otherv pipe h of the `fluid operated means for actuating the first slide c is` connected to the pressure fluid supply pipe 38, the latter and the other pipe I8 of the operating means for the gear-controlling clutch being in communication with any convenient pressure uid supply pump (not shown) i During the trimming cycle the trimming roller ais pressed against the grinding wheel b and' is rotated by the latter which is driven at a suitably slow rate from the motor o.- At the same Atime the roller a is caused to travel along the helix of the wheel bi by the motion of the slide d under the action ofthe screw z'. In-'this `condi- 'tion the pipes g, I9 are connected by the valve 30 to the pressure-fluid supply pipe 38,'and the 'shadow motor o drivesthe screwat a relatively lslow rate through the parts, q, r. P, r. 10,'8, vil, 2. 2, i. 3. l, u, 6 and 6. 4O'n thev slide dvreaching the end of its travel the sliclable member ,32 of the tappet mechanism is moved by contact of the abutment `36 on this slide with the vabutment 134on the said member, and the tappet 3| actuatesthe operating member 3l of the valve' 3u to connect the pipes yg`, I9 to the exhaust pipeiil.` V'This'causes thev irs't slide c to retract the trimming roller'a from the grinding wheel b, andthe fluid pressure conveyed by` thepipe yiB causes the rack t to actuate the lever 22 and engage the slidable clutch part Il with the gean'wheel to cause the screw i to return the-second slide d quickly to its initial position, the screw1i being slide d the slidable member 32 of the tappet mechanism is returned to its initial position by contact of the abutment 36 with the other abutment 36 on the said member. andthe tappet Il releases the operating memberl of the valve lll, the latter being thus caused to connectthe pipes a, I9, to the pressure iluid supply` pipe 36, whereupon the rst slide c is caused to ad- `vance the trimming roller a into contact with the grinding wheel b. The cyclevabove described is then repeated, the trimming action being continued in successive cycles until the wheel has been properly trimmed.

In the example shown the mechanism above described is built into a grinding machine, and is mounted at the side of the grinding wheel b remote from that which operates on the work piece (notshown). For enabling this to be effected the part 1c which carries the second slide d consists of a third slide movable at right angles to the axis of the grinding wheel, this third slide serving also to carry the above described valve and tappet mechanism and screw together with the shaft u and associated parts of the mechanism for transmitting motion to the screw. The other parts of the latter mechanism together with the third slide k and the grinding wheel b are mounted on a fourth slide 46 movable in the same direction as the third slide, the fourth slide being carried` by rollers 4| on the bed 42 oi' the machine. The third slide k is movable by a hand-operable screw 4I engaging a nut 44 on this slide, and this screw is connected by gearing 45` with a rotatable shaft 46 on the` fourth slide 46, this shaft being operable through worm gearing 41 by a hand wheel 46. Also mounted on the fourth slide 40 is another screw 49 which is arranged parallel with the shaft 46 and is operable through worm gearing 56 by another hand wheel 6I.. In engagement with the screw 49 is a nut 62 carried by a bearing 53 through which pass both this screw and the shaft 46. 'I'he nut 62 is connected by a pair of interengaging gear wheels 64 to a bush 56 mounted in the bearing 53 and slidably splined on the shaft 46. The bearing 53 is carried by a pair of parallel cylinders 66 formed integrally with or connected to each other and slldably mounted on a ,pair of fixed plungers 51 and supports 58 in the bed 42 of the machine. Pressure fluid acting in one of the cylinders 56 causes the fourth slide 40 and all the other slides c, d, and k mounted on it to be moved simultaneously in the direction for carrying the grinding wheel b away from the work piece, and fluid pressure acting in the other cylinder 56 has the reverse 3 erect.. Rotation or the shaft u by its hand wheel 48v causes the nut 62` and the screw 43 associated with the third slide k to be rotated,

so causingthe third slide to move on the fourth slide 46 and the latter to move to an equal extent on the bed 42. Rotation of the screw 49 by its hand wheel 5I causes the fourth slide `4l) to move carrying the third slide k with it.

The movements of the hand wheels 48, 5l serve to effect adjustments of the positions of the "trimming roller a and grinding wheel b relatively to each other and to the work piece.

` The invention is not limited to the example above described as'subordinate'mechanical details may be 'varied to suit different conditions,

' and the application of the invention to the grinding of splined shafts, worms and the other like bodies is essentially' similar, the shape of the trimming roller being in all cases made to correspond with the cross sectional configuration of the helix of the grinding wheel'. Moreover, whilst y it is usually preferable to employ la freely rotatable trimming roller, this roller may sometimes be positively rotated.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. Means for trimming a helically shaped' actuating the second slide, means for rotatingy the grinding wheel and the reversible screw mechanism, a fluid operable clutch forcontrolling the action of the reversible screw mechanism, the clutch having component parts which so far at least as the movement of the second slide in the operative direction is concerned, are interengageable only when in predetermined relative positions, valve and tappet mechanism operable by the second slide for controlling the said uid operable means and the clutch, a third slide carrying the second slide and movable in the same direction as the first slide, a fourth slide carrying and movable in the same direction as the Athird slide, a bed carrying the fourth slide, hand operable means for moving the third and fourth slides together and relatively to each other, and fluid operable means for moving the fourth slide together with the third slide.

2. Means for trimming a helically shaped periphery of a grinding wheel, comprising the combination of a rotary trimming roller adapted to effect the required trimming by a crushing action on the grinding wheel, a ,slide on which the trimming roller is mounted, and which is movable towards and away from the periphery of the grinding wheel, anotherslide which carries the ilrst slide and is movable in a direction along the periphery of the grinding wheel, means for actuating the iirst slide, a reversible mechanism for actuating the second slide, means for rotating thegrinding wheel and the reversible mechanism, a clutch for controlling the action of the reversible mechanism, means associated with the second slide for controlling the movements of both slides and thereby causing the trimming 4 y V roller to pass through successive operation-cycles automatically, a third slide carrying the second slide and movable in a direction towards and away from the periphery of the grinding wheel, a fourth slide carrying and movable in ,the same direction as the third slide, a bed carrying the fourth'slide, and means for moving the third and fourth slides either jointly or independently.

3. Means for trimming a helically shaped periphery of a grinding wheel, comprising the combination of a rotary trimming roller adapted to effect the required trimming by a crushing action on the grinding Wheel, a slide on which the trimming roller is mounted, and which is movable towards and away from the periphery of the grinding wheel, another slide which carries the first slide and is movable in a direction along the periphery of the grinding wheel, means for actuating the first slide, a reversible mechanism for actuating the second jslide, means forgo rotating the grinding wheel and the reversible mechanism, a clutch for controlling the action aasaom operable kshaft mounted on the fourth slide, gear- 'ing connecting the shaft to the screw, a second and hand operable screw mounted on the fourth slide and arranged parallel with the shaft, a nut on the second screw, `a bush slidable on the shaft, gearing interconnecting the bush and the nut on the second screw, and fluid operable means carrying the bush and the nut on the second screw. AXEL CHARLES WICKMAN. 

